Conventionally, this type of sunroof apparatus has been well known (see, for example, Patent Document 1). The above-described opening/closing mechanism of the sunroof apparatus usually includes a support member fixed to the roof panel, a guide rail fixed to the fixed roof, and extending in a longitudinal direction of the vehicle, a movable member movable along the guide rail in the longitudinal direction of the vehicle, a cam groove provided in one of the support member or the movable member, and including an upper cam surface and a lower cam surface facing each other in the vertical direction and extending in the longitudinal direction of the vehicle, and a pin provided in the other one of the support member or the movable member to project in a vehicle width direction, being engaged with the cam groove, and relatively sliding on the upper and lower cam surfaces of the cam groove by movement of the movable member. Relative slide movement of the pin on the upper and lower cam surfaces of the cam groove obliquely moves the roof panel. In the Patent Document 1, a resin collar (roller) is interposed between the pin and the cam groove.